• 제목/요약/키워드: Quasi-state

검색결과 502건 처리시간 0.026초

Feasible and Invariant Sets For Input Constrained Linear Parameter Varying Systems

  • Lee, Young-Il
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.1911-1916
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    • 2003
  • Parameter set of an LPV system is divided into a number of subsets so that robust feedback gains may be designed for each subset of parameters. A concept of quasi-invariant set is introduced, which allows finite steps of delay in reentrance to the set. A feasible and positively invariant set with respect to a gain-scheduled state feedback control can be easily obtained from the quasi-invariant set. A receding horizon control strategy can be derived based on this feasible and invariant set.

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1MHZ 공진형 DC - DC 콘버터 (ZERO - VOLTAGE - SWITCHED QUASI - RESONANT DC - DC CONVERTER WITH 1MHZ SWITCHING FREQUENCY)

  • 이윤종;김희준;안태영
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1988년도 추계학술대회 논문집 학회본부
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    • pp.381-384
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    • 1988
  • This paper analysed basic operation in Zero-voltages-switching quasi-resonant buck converter and considered steady state characteristics. Especially, it is confirmed that converter operating at maximum 1MHz switching frequency in load characteristics. In this paper, a novel slope method is proposed and implemented in regulation characteristics analysis. It is proved that experimenental results coincide with theory results.

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SOME RESULTS ASSOCIATED WITH CERTAIN ANALYTIC AND UNIVALENT FUNCTIONS INVOLVING FRACTIONAL DERIVATIVE OPERATORS

  • Irmak, H.;Raina, R.K.
    • East Asian mathematical journal
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    • 제21권2호
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    • pp.219-231
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    • 2005
  • This paper investigates some results (Theorems 2.1-2.3, below) concerning certain classes of analytic and univalent functions, involving the familiar fractional derivative operators. We state interesting consequences arising from the main results by mentioning the cases connected with the starlikeness, convexity, close-to-convexity and quasi-convexity of geometric function theory. Relevant connections with known results are also emphasized briefly.

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ON THE STABILITY OF RECIPROCAL-NEGATIVE FERMAT'S EQUATION IN QUASI-β-NORMED SPACES

  • Kang, Dongseung;Kim, Hoewoon B.
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제26권2호
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    • pp.85-97
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    • 2019
  • In this paper we introduce the reciprocal-negative Fermat's equation induced by the famous equation in the Fermat's Last Theorem, establish the general solution in the simplest cases and the differential solution to the equation, and investigate, then, the generalized Hyers-Ulam stability in a $quasi-{\beta}-normed$ space with both the direct estimation method and the fixed point approach.

고출력 CW Nd:YAG 레이저를 이용한 CSP 1N 박판 절단공정의 열전달 특성 분석 (A Study on Heat Transfer Characteristics of Laser Cutting for the CSP 1N Sheet Using High-power CW Nd:YAG Laser)

  • 안동규;김민수
    • 한국기계가공학회지
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    • 제5권1호
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    • pp.51-58
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    • 2006
  • The objective of this research work is to investigate into heat transfer characteristics of the laser cutting of CSP 1N sheet using high power CW Nd:YAG laser. In order to investigate the heat transfer characteristics, three dimensional quasi stationary and steady-state heat transfer analysis has been carried out. The laser heat source is assumed as a volumetric heat source with a gaussian heat distribution in a plane. Through the comparison of the results of analyses with those of experiments, the proper finite element model has been obtained. In addition, characteristics of the three-dimensional heat transfer and temperature distribution have been estimated by the finite element model. Finally, the minimum temperature at the center for cutting of the material has been estimated.

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Electrospun TiO2 Electrodes for Quasi-Solid State Dye- sensitizedSolar Cell

  • Song, Mi-Yeon;Ahn, Young-Rack;Jo, Seong-Mu;Kim, Dong-Young
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.65-66
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    • 2006
  • [ $TiO_2$ ] single crystalline nanorods are prepared from electrospun fibers which are composed of nanofibrils with an island-in-a-sea morphology. The mechanical pressure produces each fibril into nanorods which are converted to anatase single crystals after calcinations. HRTEM shows that the (001) plane is growing along the longitudinal direction of the rod. In this work, the nanorod electrode provides the efficient photocurrent generation in a quasi-solid state dye-sensitized solar cells (DSSCs) using highly viscous PVDF-HFP based gel electrolytes. The overall converision efficiency of the $TiO_2$ nanorods shows 6.2 % under $100\;mW/cm^2$ (AM 1.5G) illumination.

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비선형 불규칙 진동 보의 등가에너지법에 의한 선형화 (Linearization of Nonlinear Random Vibration Beam by Equivalent Energy Method)

  • 이신영
    • 한국공작기계학회논문집
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    • 제17권1호
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    • pp.71-76
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    • 2008
  • Nonlinear dynamic system under random excitation was analyzed by using stochastic method. A linearization method was used in order to linearize non-linear structural characteristics but the parametric excitation was used as it was given. An equivalent energy method which equalizes the expectation value of energy of the original nonlinear system and that of quasi-linearized system was proposed. Ito's differential rule was applied to obtain steady state moments. Quasi-linearization coefficients can be obtained the iterative calculation of linearization scheme and steady state moments. Monte Carlo simulation was used to verify the results of the proposed method. Nonlinear vibration of a slender beam was analyzed in this research. The analysis results were compared with Monte Carlo simulation result and showed good agreement. As the spectral density of the given excitation increased, the analysis results showed the better agreement with Monte Carlo simulation.

Quasi-solid state electrolytes with silica nanomaterial for high efficiency dye-sensitized solar cells

  • Jeon, Semina;Lim, Jeongmin;Han, Chi-Hwan;Jun, Yongseok
    • Rapid Communication in Photoscience
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    • 제2권3호
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    • pp.85-88
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    • 2013
  • Silica nanoparticles were synthesized with various silane coupling agents to make specific pathway of electrons and anti-recombination system when solidifying liquid electrolytes. In this study, we used an appropriate method of synthesis for activated silica nanoparticles and silane coupling agents with 3-(triethoxysilyl)propionitrile, Trimethoxy[3-(methylamino)propyl]silane, Triethoxyoctylsilane, and octadecyltrimethoxy silane. Dye-sensitized solar cells using solidified electrolytes with silica nanoparticles exhibit comparatively excellent efficiency, ranging from 2.3 to 7.0% under similar conditions.

Control Strategy against Undesirable Zone 3 Relay Operation in Voltage Instability

  • Lee Byong-Jun;Song Hwa-Chang
    • KIEE International Transactions on Power Engineering
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    • 제5A권2호
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    • pp.144-151
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    • 2005
  • This paper presents a framework for determining control strategies against unwanted tripping actions during relay operation that plays a very important role in cascading events leading to voltage collapse. The framework includes an algorithm for quick identification of possible zone 3 relay operation during voltage instability. Furthermore, it comes up with the control strategy of load shedding at the selected location with active power and relay margin criteria. In addition, Quasi Steady-State (QSS) simulation is employed to obtain time-related information that is valuable in the determination of control strategy. As a case study, an example applying the framework is shown with the modified New England 39-bus system.